GC Analysis method for Methamidophos in oil

[along]

Hi everybody, did anyone of you have any method to analyse the content of Methamidophos and other opp in oil. I have only an Agilent 6890N GC and FPD detector.
Any suggestion on the FPD setting, I cannot get a good peak respond on this compound and other OPP as well.
I am using Supelco 1701 column, they claim that this is the best column for OP analysis, any comment?

Thanks

[Ron]

It sounds like you may be having issues with quenching of the sulfur response due to co-eluting hydrocarbon compounds. You could try a different column, but the first thing I would do is to increase the air flow into the detector slightly. This will have an effect on the sensitivity of phosphorus detection, but should help reduce quenching and may provide better response.

[dcobice]

hi, well that issue is difficult because of the matrix, but I have a bit experiencie about PAH in oil and I was development a suitability clean up for these.I prepared a preparative column with fluorisil and Tenax ( activated after 12 hours at 120 grades) and then I disolved a great amount of sample with for example ( Ch2Cl2 but in your case its depends of the composition of the oil) and then when the solvent evaporated, I put that "tablet" at the top of the column.An hidrocarbon Its a suitability solvent to begin the eluation ( n-hexan for aliphatics, i-octane for Non-aliphaticas and benzene to aromatics), then with Opp such as Ch2cl2 is a good idea.

Perhaps I will hope these help!

Thanks